The AP you have now is 802.11n (wifi 4).
What matters is what your new network needs to meet, what clients are they using and what are any future plans?
You also need to think about how much speed is needed? Where is coverage needed ? How many streams do the clients use ? What about the technology used such as calling over VOIP ? Etc etc etc.
Each AP has its own transmission pattern and a one to one replacement is not recommended.
With this information, I recommend that you have a design created and then tested through a survey after completion.